Solid-state storage, as well as other forms of data storage media, is subject to failure or data error on specific regions within the solid-state storage. In other instances, an entire device or chip is defective and nonfunctional. Often, a plurality of memory devices or storage elements are used, such as in a distributed redundant array of independent drives (“RAID”) or other redundant data system. An array of memory devices such as a RAID system provides a level of protection against data errors and device failures, as parity data stored in the array can be used to replace failed data.
In a typical RAID system, if a data device fails, the parity devices(s) are used to rebuild the data within the failed device onto a replacement data device. If a parity device fails, the data in the data devices is used to rebuild the parity data in a replacement parity device.
Typically, a RAID system provides data protection in the event that a certain number of data or parity devices fail. If these devices are not replaced, and the number of defective devices falls below the certain number of failed devices that the RAID system accommodates, data will be lost.